Soils and layers
Perlite
Reusable
White puffed volcanic glass. Keeps soil light and open.
What the simulation uses
- Holds water
- 25 % by volume
- Water it keeps after draining; the rest runs down to the drainage.
- Pore space
- 85 % by volume
- Room for air and water between grains; low means roots suffocate when wet.
- Weight
- 90 g/L
- How heavy a litre is.
- pH
- 6.5 to 7.5 pH
- How acid it keeps the soil.
- Mould risk
- none
- How much fresh food it gives white mould; high-risk soils fuzz over in the first weeks.
- Nutrients
- none
- Plant food it brings.
- Presses down to
- 88 % of its loose depth
- How far pressing can pack it, keeping its weight.
Description
Volcanic glass heated until it pops, swelling up to sixteen times its size. It holds little water and lets air into soil mixes. It is so light that it floats to the top if the jar floods.
Also called expanded perlite.
Estimated, where sources were thin: porosity, water holding, AFP and pH from general literature, not a fetched datasheet.